:gem: bump to 1.5.3
:gem: bump to 1.5.3

gjtorikian/html-proofer,Tiger66639/html-proofer,gjtorikian/html-proofer,gjtorikian/html-proofer,Tiger66639/html-proofer,gjtorikian/html-proofer,Tiger66639/html-proofer,Tiger66639/html-proofer,gjtorikian/html-proofer,Tiger66639/html-proofer